A series of chiral (optically active) surfactants will be prepared in highly purified forms. The surface properties of both enantiomers of the surfactants will be compared and purification continued until their behavior is identical. Particular use will be made of surface film studies to compare the intermolecular stereochemistry of chiral monolayers. Differences between pure enantiomeric monolayers and racemic ones will be compared. Diastereomeric differences in mixed monolayers of chiral surfactants and the penetration or interaction of chiral molecules from the subphase into chiral monolayers will be studied. Since enantiomers are perfect stereochemical models of each other, any differences in diastereomeric interactions or between enantiomers and racemates can be attributed unequivocally to differences in intermolecular packing and not to impurities. We therefore expect to provide fundamental information on the stereochemical factors which influence intermolecular forces in condensed phases such as the behavior of molecules in monolayers, membranes and micelles.